Diquinolonopyridone

ABSTRACT

A CLASS OF COMPOUNDS OF WHICH DIQUINOLONOPYRIDONE IS ILLUSTRATIVE, AND NEW AND USEFUL PIGMENTS FORMED THEREFROM ALONG WITH A CLASS OF INTERMEDIATES OF WHICH DIMETHYYL-3,5-DIANILINOCHELIDAMATE IS TYPICAL.

United States Patent 3,586,684 DIQUINOLONOPYRIDONE Chung C. Chen,Belleville, N .J assignor to E. I. du Pont de Nernours and Company,Wilmington, Del. N0 Drawing. Filed Oct. 11, 1967, Ser. No. 674,635 Int.Cl. (307d 33/50 US. Cl. 260288 6 Claims ABSTRACT OF THE DISCLOSURE Aclass of compounds of which diquinolonopyridone is illustrative, and newand useful pigments formed therefrom along with a class of intermediatesof which dimethyl-3,S-dianilinochelidamate is typical.

BACKGROUND OF THE INVENTION The present invention provides a novel anduseful organic compound of the formula:

replacement for hydrogen in any of the four positions of each benzenoidring. Such a compound may be conveniently formed by ring closure of acompound of the formula:

H fl) H N N R1000 cooR1 (m wherein R is a member of the class consistingof hydrogen and lower alkyl.

Compound (II) is prepared by a Jordan-Ullmann condensation of adihalochelidamic acid or its lower alkyl ester with an aromatic amine ofthe formula wherein R, as defined above, may replace as many as fourhydrogens attached to ring carbon, with the proviso that at least onering carbon ortho to the amino nitrogen substituent is unsubstituted.Compound (II) is converted to (I) by ring closure in the presence ofcyclizing agent such as polyphosphoric acid (PPA). Preparation of thepigmentary form involves purification of the crude and reduction to thedesired particle size, these steps being those commonly used in pigmenttechnology. They include such methods of particle size reduction as acidpasting, acid swelling, salt milling, salt-solvent milling, solventbreaching, etc., all of which methods have been widely used in thetechnology of such popular pigments as phthalocyanines andquinacridones. The other steps related to purification of the productentail such common procedures as recrystallization, washing, filtration,etc., all of which will be illustrated in the detailed examples tofollow.

For a clearer understanding of the invention, the following specificexamples are given. These examples are intended to be merelyillustrative of the invention and not in limitation thereof. Unlessotherwise specified, all percentages and parts are by Weight.

Example 1 Dibromochelidamic acid is prepared by adding 320 parts ofbromine at a uniform rate over a 3% hour period to a suspension of 183parts of chelidamic acid in 750 parts of water at room temperature. Thetemperature rises from 21 to 37 C. and the mixture is heated to C. in 1/2 hours. It is thereafter cooled to room temperature and filtered. Thesemi-dry product recrystallized from 2000 parts of water and dried at C.is recovered in a yield of 84.8% of theory. It has a melting point above300 C.

The diester of dibrornochelidamic acid is prepared by bubbling hydrogenchloride gas into a mixture of 5 0 parts of the above acid in 200 partsof methanol for 5 minutes. The solution is refluxed for 3 hours,following which 1 part of declorizing charcoal is added. After anadditional stirring of 5-10 minutes, the solution is filtered hot, thefiltrate is distilled and, after recovery of parts of methanol, cooled.The product precipitates as a colorless solid which is recovered byfiltration and washed free of acid with water to provide a yield of88.6% of theory.

A small sample recrystallized from methanol has a melting point of112113 C. (softening at 102 C.).

To prepare a compound corresponding to Formula II above wherein R ishydrogen and there is no R substituent, (i.e. 3,5-dianilinochelidamicacid), 113.5 parts of dimethyl 3,5-dibromochelidamate, prepared asdescribed immediately above, is stirred and refluxed for 10 hours in areaction vessel along with:

Parts Ethylene glycol 330 Potassium carbonate 90 Water 75 Aniline 450Potassium iodide l5 Cupric acetate monohydrate 3 The mixture is thensteam distilled to remove the major portion of unreacted aniline, thesolution is concentrated to about 1000 parts, cooled to room temperatureand filtered to remove a small amount of a colorless precipitate. Thefiltrate is acidified with concentrated hydrochloric acid to a pH of 2or less whereupon a yellow product precipitates which is isolated byfiltration and washed with water. (Yield: 37.0 parts) When3,5-dibromodichelidamic acid is substituted in equivalent amount for theester, a similar product is obtained, the identity of the two beingdemonstarted by their infrared absorption spectra.

Diquinolonopyridone (corresponding to Formula I above wherein there isno R substituent) is prepared by heating a stirred mixture of 123.3parts of pulverized 3,5 dianilinochelidamic acid with 1,233 parts of PPAover a period of l to 1 /2 hours to 150 C. The mixture is maintained attemperature for 3 /2 to 4 hours. It is then cooled to room temperature,and water is added slowly, the rate being such as to maintain thetemperature below 60 C. The precipitated product is isolated byfiltration,

washed free of acid, and dried at 80 C. The crude product obtained isextracted with boiling dimethyl formamide (DMF), filtered hot, andwashed successively with DMF and alcohol. A yield of 101 parts of theproduct is obtained.

To prepare a pigment of diquinolonopyridone, 37 parts of thedimethylformamide (DMF) extracted crude is pulverized and dissolved in370 parts of concentrated sulfuric acid at 810 C. The acid concentrationis lowered to 75% by the gradual addition of water with stirring, therate being such as to maintain the temperature at first below 10 C. butat the end of the dilution to permit the temperature to rise to C. Theprecipitated sulfate of diquinolonopyridone is separated by filtrationand then hydrolyzed to the free diquinolonopyridone by treatment withice and water. The red product is isolated by filtration, washing freeof acid and drying. Yield: 23.3 parts.

The acid crystallization is repeated, and the product extracted twicewith 1000 parts of boiling DMF. Final yield: 14.2 parts.

The product isolated from the acid crystallization or DMF extractionshows an X-ray pattern which indicates that it is isomorphous with thebeta modification of quinacridone (cf. US. 2,844,485). A similar crystalstructure is realized when the product is reduced in particle size bysalt milling and then followed by refluxing with DMF, acetic acid,alcohol, xylene or water. Likewise, decomposition of the sodium salt ofdiquinolonopyridone in acetic acid at room temperature yields the samecrystal form. The X-ray data, showing the interplanar spacings inangstrom units, are summarized in the following table and compared withthose of the beta crystal form of linear quinacridone:

Diquinolonopyridone, A.: Beta quinacridone, A.

An entirely different crystal form of diquinolonopyridone is obtainedwhen the product is subjected to the following procedure. One part ofthe acid recrystallized, DMF extracted product is suspended in 50 partsof ethanol and 5 parts of 50% aqueous sodium hydroxide. The mixture isrefluxed for 2 /2 hours, following which it is filtered hot. Theisolated blue sodium salt is suspended in Water, whereupon some colorchange to red occurs; but complete hydrolysis is not achieved until theproduct is acidified with concentrated hydrochloric acid. An orangeproduct is isolated by filtration, washing and drying. The X-raydiffraction pattern of this product shows interplanar spacings at 14.24,6.60, 5.53, 3.64, and 3.32 angstrom units. This pattern shows somesimilarity to that of alpha-phase linear quinacridone (US. 2,844,- 484)and some to gamma-phase quinacridone (US. 2,844,581) and may conceivablybe a mixture of two crystal forms which are isomorphous with theaforementioned phases of linear quinacridone.

The acid pasted diquinolonopyridone is flushed into a linseed oilvehicle and compared to a corresponding ink prepared from a typicalgamma-phase linear quinacridone. Though somewhat duller in masstone, itshows a strength advantage over the linear quinacridone, the strength ofthe diquinolonopyridone being as high as twice that of the referencestandard, depending upon the conditions of test. The strength advantageis also observable when the pigment is dispersed in various paintvehicles, the advantage being dependent on the system in which the pigments are tested. When very bright red finishes, approximating themasstone depth and color of Toluidine Red are prepared by pigmentingwith a blend of diquinolonopyridone and Molybdate Orange, such finishesare fully as attractive as their counterparts pigmented with a blend ofbeta-phase linear quinacridone and Molybdate Orange. Furthermore, thehigher quantity of the less expensive Molybdate Orange used in the blendwith the diquinolonopyridone results in increased hiding over thecorresponding blends with linear quinacridone. It is thus obvious thatthe inherent strength advantage demonstrated in the simple comparison ofthe diquinolonopyridone with linear quinacridone is carried through intothe blends with the inorganic pigment.

Six months exposure of paint panels in Florida show thatdiquinolonopyridone has very good durability in a thermosetting acrylicenamel and is also quite good in an acrylic lacquer system. The pigmentshows nobleed in these or other paint systems in which it is tested.

Example 2 To prepare a compound corresponding to Formula II abovewherein R is hydrogen and R is p-methyl (i.e.,3,5-di-para-toluidinochelidamic acid), 113.5 parts of dimethyl3,5-dibromochelidamate is stirred and refluxed for 10 hours in areaction vessel along with 330 parts ethylene glycol, 90 parts potassiumcarbonate, parts water, 531 parts p-toluidine, 15 parts potassium iodideand 3 parts cupric acetate monohydrate. The mixture is diluted with 1000parts of water and refluxing continued for another 1% hours. It is thencooled to 20 C. and the excess precipitated p-toluidine is removed byfiltration. On acidification of the filtrate with acetic acid, the freeacid is precipitated as a yellow product. This is isolated byfiltration, washing with water, and drying. Yield: 43.3 parts.

2,10 dimethyldiquinolonopyridone is prepared by cyclization of 20 partsof pulverized 3,5-di-para toluidino chelidamic acid using 300 parts ofPPA, following the cyclization procedure of Example 1, to provide ayield of 13.7 parts.

To prepare a pigment of 2,IO-dimethyldiquinolonopyridone, 22 parts ofthe DMF extracted crude is pulverized and dissolved in 220 parts ofconcentrated sulfuric acid at 8l0 C. The acid concentration is loweredcarefully to by the gradual addition of water, and the precipitatedsulfate is isolated by filtration. This is then hydrolyzed by treatmentwith ice and water and the pigment is isolated by filtering, washingacid free and drying. Yield: 13.0 parts.

The product is acid pasted and flushed into linseed oil vehicle andfound to compare very closely in both color and strength with the parentunsubstituted diquinolonopyridone.

Paint tests in acrylic enamel show the product to be yellow and strongvs. a standard -quinacridone toner (US. Pat. 2,844,581). The purifiedproduct is salt milled and the powder refluxed in various solvents suchas DMF, acetic acid, alcohol, xylene, and water. The crystal form mostoften encountered shows interplanar spacings by X- ray diffraction at17.3, 10.5, 7.37, 6.02, 5.40, 4.72, 4.39, 3.86, 3.70, and 3.32 angstromunits. The product refluxed in xylene shows an additional peak of mediumintensity at 11.94 angstrom units. The product extracted in water onlyshows a peak at 5.75 angstrom units, but no other significantdifferences. The DMF refluxed pure product is considerably yellower thanits acid pasted counterpart and is quite strong.

Example 3 To prepare a compound corresponding to Formula II abovewherein R is hydrogen and R is p-chloro (i.e., 3,5-di-para-chloroanilinochelidamic acid), 91.2 parts of 3,5-dibromochelidamate is stirred and refluxed for 10 hours with 264 partsethylene glycol, 72 parts potassium carbonate, 60 parts water, 492 partsp-chloroaniline, 12 parts potassium iodide and 2.4 parts cupric acetatemonohydrate. The mixture is diluted with 800 parts of water andrefluxing continued for another 1% hours. It is then cooled toapproximately 20 C. and filtered to remove the excess p-chloroaniline.The filtrate is acidified with acetic acid, wherein a yellow productprecipitates. This is isolated by filtration, washing, and drying.Yield: 24.0 parts.

2,10-dichlorodiquinolonopyridone is prepared by cyclization of 45.7parts of pulverized 3,5-di-parachloroanilinochelidamic acid using 500parts of PPA, following the cyclization procedure of Example 1, toprovide a yield of 29.5 parts.

To prepare a pigment of 2,10-dichlorodiquinolonopyridone, 22 parts ofthe DMF extracted crude is pulverized and dissolved in 500 parts of 100%sulfuric acid at 5l0 C. The acid concentration is lowered to 97% withwater and the precipitated sulfate is isolated by filtration. It is thenhydrolyzed by treatment with ice and water. The resulting pigment isisolated by filtration, washing free of acid and drying. Yield: 10.5parts.

The product is acid pasted and flushed into a linseed oil vehicle. Itwas found to be strong but dull versus 2,9-dimethylquinacridone; alsoduller and bluer than the unsubstituted parent diquinolonopyridone.

In acrylic enamel the product is yellow and slightly slightly strongversus -quinacridone, and blue versus the dimethylquinolonopyridone.

Typical X-ray diffraction patterns of products finished by various waysshow interplanar spacings at 16.98, 5.90, 5.27, 4.87, 4.48, 4.09, 3.77,3.59, and 3.22 angstrom units.

Example 4 To prepare a compound corresponding to Formula II abovewherein R is hydrogen and R is para-methoxy (i.e.,3,S-di-para-anisidinochelidamic acid), 68.4 parts of dimethyl3,5-dibromochelidamate is stirred and refluxed for hours with 198 partsethylene glycol, 54 parts potassium carobnate, 45 parts water, 37 partsp-anisidine, 9 parts potassium iodide and 1.8 parts cupric acetatemonohydrate. The mixture is then diluted with 600 parts of water andrefluxing continued for an additional 1 /2 hours. The reaction mixtureis cooled to about C. and the precipitated excess amine removed byfiltration. Upon acidification with acetic acid, the free acid ispercipitated as a dark yellow solid. This is isolated by filtration,washing free of acid, and drying. Yield: 61.1 parts.

2,10-dimethoxydiquinolonopyridone is prepared by cyclization of 62.4parts of pulverized 3,5-di-para-anisidinochelidamic acid using 1000parts of PPA, following the cyclization procedure of Example 1, exceptthat the mixture is stirred and heated rapidly to 125-130 C. andmaintained at this temperature for only 7 minutes, after which it isthen cooled rapidly and worked up in the usual manner. A yield of 44.5parts is obtained.

To prepare a pigment of 2,10-dimethoxydiquinolonopyridone, 20 parts ofthe DMF extracted crude is pulverized and dissolved in 300 parts ofconcentrated sulfuric acid at 810 C. The acid concentration is loweredto 90% by theg radual addition of water at such a rate as to maintainthe temperature at 10 C. or lower initially and not above 15 C. at theend of the dilution. The precipitated sulfate is filtered andsubsequently hydrolyzed by treatment with ice and water. The pigment isisolated by filtration, washing free of acid, and drying. Yield: 13.0parts.

Comparison of the flushed acid pasted product with the unsubstituteddiquinolonopyridone shows it to be fully as strong as the latter, butsomewhat duller.

In acrylic enamel the product is slightly yellow and weak vs. thedimethyl counterpart.

When the product is salt milled and refluxed in various solvents, it isfound that the mixture which is extracted with water gives a markedlydifferent X-ray pattern (alpha phase) than those refluxed in DMF, aceticacid, alcohol or xylene (beta phase). The interplanar spacings derivedfrom the X-ray diffraction patterns are shown in the following table:

Alpha phase, A.: Beta phase, A.

To prepare a compound corresponding to Formula II above wherein R ishydrogen and R is m-methyl (i.e., 3,5-di-metatoluidinochelidamic acid),75.9 parts of dimethyl 3,5-dibromochelidamate is stirred and refluxedfor 10 hours with 220 parts ethylene glycol, 60 parts potassium 9Ocarbanate, 50 parts water, 177 parts m-toluidine, 10 parts potassiumiodide and 2 parts cupric acetate monohydrate. The reaction mixture issteam distilled to remove the eX- cess m-toluidine, and the volumeconcentrated to about 500 parts. It is then cooled and filered to removethe small amount of insoluble material which forms. The filtrate isacidified with acetic and the small amount of precipitate formed removedby filtration. Then the filtrate is acidified with concentratedhydrochloric acid to a pH of 1 or less, whereupon a bright yellowprecipitate is formed. This is isolated by filtration, washing free ofacid, and

drying. Yield: 20.3 parts.

3,9-dimethyliquinolonopyridone is prepared by cyclization of 72.0 partsof pulverized 3,5-di-meta-toluidinochelidamic acid using 800 parts ofPPA following the cyclization procedure of Example 1 to provide a yieldof 61.7 parts.

To prepare a pigment of 3,9-dimethyldiquinolonopyridone, 24.6 parts ofthe DMF extracted crude is pulverized and dissolved in 492 parts of97.5% sulfuric acid at a temperature below 10 C. The concentration ofacid is lowered to 70% by the careful addition of Water. Theprecipitated sulfate is filtered and subsequently hydrolyzed bytreatment with ice and water. The resulting precipitated pigment isisolated by filtration, washing free of acid, and drying. Yield: 8.3parts.

The X-ray diflraction pattern of the DMF extracted product is differentfrom that of the acid recrystallized counterpart, indicating theexistence of at least two crystal phases.

MODIFICATIONS AND EQUIVALENTS Although the specific examples arerestricted to dibromochelidamic acid as the initial starting material,nevertheless other halogenated derivatives such as the iodinated orchlorinated counterparts may be used. The actual choice will bedetermined largely by considerations of cost as well as the ability ofthe intermediate to undergo satisfactorily the subsequent Jordan-Ullmanncondensation with the particular aromatic amine. The choice of aromaticamine is not intended to be restricted to those actually shown in theexamples, but may include other primary aromatic amines, such assubstitution products of aniline, amines, etc. It is necessary, ofcourse, that one of the positions in the aromatic ring ortho to theprimary amino group be unsubstituted so as to permit the subsequentcyclization.

A large number of satisfactory cyclizing agents will be suggested tothose familiar with related art, such as the synthesis of quinacridone.Among these may be mentioned anhydride;

acid halides, such as benzoyl chloride, benzoyl bromide,

phosgene, benzotrichloride, thionyl chloride, phosphorus pentachloride,phosphorus oxychloride;

acid salts, such as anhydrous aluminum chloride, titanium chloride,sodium acid sulfate;

sulfonated alkyl or aromatic compounds, and heat per se.

The cyclization may optionally be conducted in an inert solvent diluent,such as trichlorobenzene, nitrobenzene, Dowtherm A (a eutectic mixtureof biphenyl and diphenyl ether), etc.

The conditions for the synthesis and ultimate processing of the productsmay be varied as required by the particular compound desired.

ADVANTAGES OF THE INVENTION relatively expensive organic component insuch blends along with the inorganic, such as Molybdate Orange.

These pigments may be used in all applications where colored pigmentsare employed. Such applications include printing ink, paint, paper,coating, plastics, rubber, mass pigmentation of synthetics, etc. Theusual well known methods of conditioning the surface of pigments foradaptation to particular systems are applicable.

What is claimed is: 1. The compound wherein R is a member of the classconsisting of lower alkyl, lower alkoxy and halogen and, when present,is replacement for hydrogen in any of the four positions of eachbenzenoid ring.

2. The compound of claim 1 wherein R is methyl in the 2,10 positions.

3. The compound of claim 1 wherein R is methyl in the 3,9 positions.

4. The compound of claim 1 wherein R is chloro in the 2,10 positions.

5. The compound of claim 1 wherein R is methoxy in the 2,10 positions.

6. The compound of claim 1 wherein no R substituent is present.

References Cited UNITED STATES PATENTS 3,107,248 10/1963 Cooper 260 2793,124,581 3/1964 Bottler 260-279 3,334,102 8/1967 Aldridge 2602883,372,184 3/1968 Auster 260-471 DONALD G. DAUS, Primary Examiner US. Cl.X.R.

